The invention concerns an apparatus for the manufacture or finishing of a fiber band, such as for a drawing frame or a carding process, wherein the fiber band is conducted between two feeler rolls. The feeler rolls are adjustable in a radial direction to achieve a preset distance of separation for the measurement of fiber band thickness, and at least one of the rolls is driven by a shaft.
An apparatus of this class, such as, for instance, the Regulier drawing frame RSB 951 of the firm Rieter Ingolstadt Spinnereimaschinenbau AG, shows for the measurement of the thickness of the fiber belt, a pair of feeler rolls, which are variable in their spatial interval, one from the other. The fiber band which is conducted through the feeler roll pair activates the distance of the one feeler roll from the other more or less in accord with the thickness of the fiber band. The rolls, which are pressed against each other by means of springs, follow the varied thicknesses of the fiber band which is between them. The fiber band thickness which has been so registered, is transmitted to the control of the machine or at least brought to a display. By means of the determination of the fiber band thickness, the manufacturing procedure can be improved, in that a fiber band with an extremely even thickness can be made, when the machine is operated in adjustment, that is, in the chosen stretch of the fiber band. Pairs of feeler rolls of this kind are found on the input side and/or on the output side of a drawing frame. At the drawing frame entrance, the thickness of the fiber band which is on the point of entering the frame is measured. In accord with this measurement, single drawing frame pairs of rolls are more or less accelerated, so that too thick a fiber band is reduced in thickness and a too thin a fiber band is less strongly stretched, whereby its thickness is increased. At the draw frame exit end, an additional pair of feeling rolls can be found, which are frequently called a pair of calender rolls. These determine the result of the drafted fiber band. At this point, a quality control operation of the extended fiber band is carried out.
These measurement based results can serve for statistic evaluation as well as also for an input to the regulation of the drawing frame.
Very often, a stationary feeler roll is arranged as one of a feeler roll pair. The second feeler roll is designed to be radially pivotable, in order that it may be disengaged in case of an uneven fiber band. The pivotable feeler plate is furthermore driven to avoid slip of the fiber band between the feeler rolls and thus, in an unfavorable case, to avoid a faulty draft of the fiber band.
In order to achieve especially good measurement results with a feeler roll pair of this description, it is important that the feeler rolls can quickly follow a fiber band of fast changing thickness. A detriment of the conventional embodiment is that the pivotable feeler plate and the drive mechanism are affixed to a pivotable bearing block. The complete assembly is relatively heavy and because of its high inertia, results in a relatively sluggish response reaction as the thickness of the fiber band changes. Even by modern equipment of this generic type and driven at very high loading rates, the changing fiber band thickness cannot be tracked with the required precision.